This invention relates to an apparatus and process for aligning elements of a drive train of a vehicle, especially a heavy-duty, load-carrying vehicle, but not limited thereto, and is particularly directed to apparatus and method for aligning the drive shaft and the rear axle of a vehicle.
Heavy-duty, load-carrying vehicles commonly have an articulated drive shaft connected by a driven spline or like connecting means with a transmission and by a drive spline or like connecting means with a differential. The drive shaft is articulated by means of a universal joint to accommodate the up and down motion of the differential according to the load placed on the vehicle and the uneveness of the terrain. The differential drives a rear axle which has right and left components driving right and left rear wheels.
Optimally the drive shaft is aligned in a vertical plane through the two splines and the rear axle is normal to this plane. The part of the drive shaft between the driven spline and the universal joint optimally is in a plane parallel to the frame of the vehicle or the ground. However, due to heavy loads and rough usage, and sometimes to improper servicing, the drive shaft tends to become displaced out of its optimal vertical alignment and the front section out of its optimal horizontal alignment. Sometimes, also, new vehicles have sub-optimal alignments in the drive train, whether due to careless workmanship or to the lack of adequate equipment to effect optimum alignment.